Search

The study of behaviour is dominated by two approaches. On the one hand, ethologists aim to understand how behaviour promotes adaptation to natural contexts. On the other, neuroscientists aim to understand the molecular, cellular, circuit and psychological origins of behaviour. These two complementary approaches must be combined to arrive at a full understanding of behaviour in its natural setting. However, methodological limitations have restricted most neuroscientific research to the study of how discrete sensory stimuli elicit simple behavioural responses under controlled laboratory conditions that are only distantly related to those encountered in real life. Fortunately, the recent advent of neural monitoring and manipulation tools adapted for use in freely behaving animals has enabled neuroscientists to incorporate naturalistic behaviours into their studies and to begin to consider ethological questions. Here, we examine the promises and pitfalls of this trend by describing how investigations of rodent fear, aggression and dominance behaviours are changing to take advantage of an ethological appreciation of behaviour. We lay out current impediments to this approach and propose a framework for the evolution of the field that will allow us to take maximal advantage of an ethological approach to neuroscience and to increase its relevance for understanding human behaviour.

Multiphoton microscopy has become a powerful tool with which to visualize the morphology and function of neural cells and circuits in the intact mammalian brain. However, tissue scattering, optical aberrations and motion artifacts degrade the imaging performance at depth. Here we describe a minimally invasive intravital imaging methodology based on three-photon excitation, indirect adaptive optics (AO) and active electrocardiogram gating to advance deep-tissue imaging. Our modal-based, sensorless AO approach is robust to low signal-to-noise ratios as commonly encountered in deep scattering tissues such as the mouse brain, and permits AO correction over large axial fields of view. We demonstrate near-diffraction-limited imaging of deep cortical spines and (sub)cortical dendrites up to a depth of 1.4 mm (the edge of the mouse CA1 hippocampus). In addition, we show applications to deep-layer calcium imaging of astrocytes, including fibrous astrocytes that reside in the highly scattering corpus callosum.

The relation between dietary fibre and the well-being of human and other monogastrics has recently became a hot topic as shown by the increasing number of publications of the related research. The aim of this review is to describe - through a logical approach - the scientific suggestion linking possible benefits of dietary fibre on nutritional components and their effect on the gastrointestinal composition in relation to disease conditions in humans and animals. Dietary fibre plays a key role in: influencing blood glucose or insulin concentrations, stool bulkiness, reducing the pH within the digestive tract, synthesising volatile fatty acids (VFA), reducing intestinal transit time, stimulating growth of intestinal microbes, and constructively enhancing various blood parameters. The available literature suggests that fibre influences the bioavailability of nutrients and maintains the host's well-being by controlling disorders and disease prevalent with a Western way of living such as constipation and diarrhoea, diabetes, obesity, gastrointestinal inflammation, atherosclerosis, and colon cancer. Although there are some studies demonstrating that dietary fibre may be effective in the prevention and treatment of these disorders, the mechanisms involved are yet to be understood.

The final stage of brain development is associated with the generation and maturation of neuronal synapses. However, the same period is also associated with a peak in synapse elimination — a process known as synaptic pruning — that has been proposed to be crucial for the maturation of remaining synaptic connections. Recent studies have pointed to a key role for glial cells in synaptic pruning in various parts of the nervous system and have identified a set of critical signalling pathways between glia and neurons. At the same time, brain imaging and post-mortem anatomical studies suggest that insufficient or excessive synaptic pruning may underlie several neurodevelopmental disorders, including autism, schizophrenia and epilepsy. Here, we review current data on the cellular, physiological and molecular mechanisms of glial-cell-dependent synaptic pruning and outline their potential contribution to neurodevelopmental disorders.

The authors describe cortical projections mediating the modulation of social behavior. Neural projections from the medial prefrontal cortex to the dorsal periaqueductal gray play a critical role in the behavioral adaptation to social defeat in mice.

How fear is represented in the brain has generated a lot of research attention, not only because fear increases the chances for survival when appropriately expressed but also because it can lead to anxiety and stress-related disorders when inadequately processed. In this review, we summarize recent progress in the understanding of the neural circuits processing innate fear in rodents. We propose that these circuits are contained within three main functional units in the brain: a detection unit, responsible for gathering sensory information signaling the presence of a threat; an integration unit, responsible for incorporating the various sensory information and recruiting downstream effectors; and an output unit, in charge of initiating appropriate bodily and behavioral responses to the threatful stimulus. In parallel, the experience of innate fear also instructs a learning process leading to the memorization of the fearful event. Interestingly, while the detection, integration, and output units processing acute fear responses to different threats tend to be harbored in distinct brain circuits, memory encoding of these threats seems to rely on a shared learning system.

This article summarizes the current data on packed red blood cell transfusion in the pediatric intensive care unit setting to help providers make evidence-based decisions regarding packed red blood cell transfusions.

In standard diffraction experiments, ensembles of objects are characterized yielding averaged, statistical properties (meaningful only if the ensemble is monodisperse). Focused x-ray beams are used here to localize single nanostructures, identifying and probing individual objects one by one. In a scanning mode, a 2-dimensional image of the sample is recorded, which allows the reproducible alignment of a specific nanostructure for analysis. The x-ray scattered signal is analyzed and modelled, to give access to the shape, strain and composition inside the single object with sub-micron resolution. Combination of x-ray microdiffraction technique with other micro-probe experiments on the very same individual object (simultaneous coupling of x-ray diffraction measurements with atomic force microscopy (AFM)) is also shown; we prove the possibility to interact with the objects and to address elastic properties for individual nano-structures out of an ensemble.

Ferrocene is a popular template in material science due to its exceptional characteristics that offer the ability to optimize the selectivity and activity of catalysts by the addition of carefully selected substituents. In combinatorial catalyst development, the high susceptibility to electrophilic substitution reactions offers the opportunity for the rapid introduction of molecular diversity. Mass spectrometry (MS)‐based continuous‐flow systems can be applied to rapidly evaluate catalyst performance as well as to (provisionally) identify the introduced catalyst complexes. Herein, we describe the fragmentation characteristics of the [ferrocenyl bidentate + Ag]+catalyst complexes in dedicated (high‐resolution) MSnexperiments. The investigation of the fragmentation patterns of a selected number of catalyst classes is accompanied with a density functional theory investigation of fragmentation intermediates in order to assess the viability of a selected fragmentation mechanism. Copyright © 2010 John Wiley & Sons, Ltd.

Surface plasmon resonances of arrays of parallel copper nanowires, embedded in ion track-etched polycarbonate membranes, were investigated by systematic changes of nanowires’ topology and arrays area density. The extinction spectra exhibit two peaks which are attributed to interband transitions of Cu bulk metal and to a dipolar surface plasmon resonance, respectively. The resonances were investigated as a function of wire diameter and length, mean distance between adjacent wires, and angle of incidence of the light field with respect to the long wire axis. The dipolar peak shifts to larger wavelengths with increasing diameter and length, and diminishing mean distance between adjacent wires. Additionally, the shape effect on the dipolar peak is investigated.

Optimising synthetic conversions and assessing catalyst performance is a tedious and laborious endeavour. Herein, we present an automated alternative to the commonly applied sequential approaches that are used to increase catalyst discovery process efficiencies by increasing the number of entities that can be tested. This new approach combines conversion of the reactants and determination of product formation into a single comprehensive reaction detection system that can be operated with minimal catalyst and reactant consumption. With this approach, rudimentary reaction conditions can be quickly optimised and the same system can then be used to screen for the optimal homogenous catalyst in a selected solution‐phase synthetic conversion. The system, which is composed of standard HPLC components, can be used to screen catalyst libraries at a repetition rate of five minutes and can be run unsupervised. The sensitive mass spectrometric detection that is implemented in the reaction detection methodology can be used for the simultaneous monitoring of reactants, catalysts and product ions. In the experiments, the three‐component reaction that gives a substituted 2‐imidazoline was optimised. Afterwards, the same method was used to assess a library of ferrocene‐based Lewis acid catalysts for performance in the aforementioned conversion in six different solvents. We demonstrate the feasibility of using this methodology to directly compare the performance results obtained in different solvents by calibrating the solvent‐specific MS responses.

Abstract:: Recent mass measurements show a substantial weakening of the binding-energy difference δ2p(Z, N) = E(Z - 2, N) - 2E(Z, N) + E(Z + 2, N) in the neutron-deficient Pb isotopes. As δ2p is often attributed to the size of the proton magic gap, it might be speculated that reduction in δ2p is related to a weakening of the spherical Z = 82 shell. We demonstrate that the observed trend is described quantitatively by self-consistent mean-field models in terms of deformed ground states of Hg and Po isotopes.

Large-scale systems that are composed of multiple sensors require the utilization of innovative methods for real-time system state estimator implementation. In fact, the classical approach of centralized estimation cannot provide satisfactory performance, since it requires the transmission of all sensor observations to a central location at large communication bandwidth. Therefore, a decentralized estimation system that distributes the processing is currently the focus of much attention. The gain transfer algorithm developed herein provides a method for decentralized hierarchical estimator implementation. Localized estimators process measurement observations locally within their own microprocessors. A global estimator independently receives information in the form of a Kalman gain transfer from these local systems. This global estimator models the overall system and thereby formulates the state estimates and state error covariance of global interest.

A method to solve the AGS equations in momentum space is presented. The two-nucleon transition operators are generated with the new Bonn potential restricted to the states1S0,3S1-3D1,3P0,1P1,3P1,3P2-3F2,1D2 and3D2. Cross sections and analyzing powers for elastic and break-up processes are calculated at a neutron laboratory energyEn=10.3 MeV.

• For the treatment of recurrent maxillary sinusitis, the middle meatus offers a good site to make an extra ostium, ie, the posterior nasal fontanel. The fontanel is situated near the natural maxillary ostium in the middle meatus, and this site is a more physiologic place, therefore, to create an antrostomy compared with the inferior meatus. Moreover, a surgical ostium has little inclination to become obliterated in this area. A special instrument was designed to perforate the fontanel. Nasoendoscopy gives an excellent view of the area and makes it possible to avoid complications.(Arch Otolaryngol 1981;107:290-293)

Not Available

Not Available

Not Available

Not Available

Not Available

Not Available

Not Available

Not Available

Not Available

Not Available

Not Available

Not Available

Not Available

Not Available

Not Available

Not Available

Not Available

Not Available

Not Available

Not Available

Not Available

Not Available

Under experimental conditions cardiac stress may induce early immediate genes. Of these, heat shock proteins like hsp 70 have been linked to preconditioning and cellular salvage. Protooncogenes like c-fos and c-jun act as transcription factors for other genes and may be involved in the regulation of programmed cell death.

Objective: Several outbreaks of multidrug resistant tuberculosis (MDR-TB) have recently occurred in which healthcare workers and others have become infected. Given the lack of clinical data to guide preventive therapy for such contacts, a Delphi survey of a panel of 31 TB therapy experts was undertaken to identify a consensus regimen.

The sensitivity of the discrete-time Kalman filter to errors in the state transition matrix is examined. The approach makes use of the matrix Taylor expansion and estimates the deviation from the 'nominal' computed performance. Although only the first term of the expansion is retained, satisfactory accuracy is achieved. The method is considerably simple and constitutes a quick way to diagnose or establish limits for divergence. Direct application to stochastic observers is also possible

In this paper, a new approach to decentralized stabilization and control is proposed. This approach combines a suboptimal high-gain output-feedback controller design with a sequential high-gain decentralized control scheme such that at each stage of the sequential scheme, the retained optimal closed loop eigenstructure has a prescribed degree of stability. This new algorithm is illustrated on a practical problem, the decentralized stabilization and control of a multi-machine power system.

The dielectric constant e' and the electrical conductivity s were measured as a function of frequency (0.1–2 MHz) and temperature for an electrolyte-polar solvent system: lithium chloride in glycerol. Mole fractions of LiCl were 0, 1, 2, 5, 10, 20, and 33.3%. Data were analysed in terms of an inverse complex permittivity(electrical modulus). At lower mole fractions, two separate modulus relaxations were observed, one due to the ionic diffusion and the other to the dipole reorientation. These two relaxation processes converged with increasing LiCl mole fraction and were not distinguishable at 20%. The moduli isotherms at 33.3% were characteristic of a fused salt. Average relaxation times and distributions for both processes were determined by computer fits to a Gaussian distribution in the logarithms of these times. Their temperature and mole fraction dependences are discussed. The conductivity relaxations became slightly broader than single at 10%; this shows the influence of the charge concentration on the structural relaxation process.